Manual

June 2004 Isis® Sonar User's Manual, Volume 2
24
B.2 GAC File Format
Q-MIPS or Isis can create Grazing Angle Compensation files, either theoretically
or empirically. The GAC files are ASCII and consist of paired multiplicative
corrections for each degree of grazing angle from 0 (far range) to 45. A sample
GAC file (
SM28.GAC) is shown in Figure B-2.
/* Grazing Angle Corrections */
46 /* number of angle bins */
01.858697 1.253826 /* grazing angle, port, starboard
corrections */
11.809185 1.233621
21.759672 1.213416
31.710160 1.193211
41.660647 1.173006
...
...
...
441.000000 1.000000
451.000000 1.000000 /* grazing angle, port, starboard
corrections */
Figure B-2. Sample GAC beam pattern file
Appendix B: Isis BAC and GAC File Formats